The invention relates to an elevator system for the transport of loads and/or persons in an elevator shaft with at least two elevator cars which can be moved in the elevator shaft and are connected to a counterweight via carrying means, wherein a drive is associated with each elevator car.
Elevator systems of this type are known from U.S. Pat. No. 1,837,643. In this case it is suggested that two cars be arranged in the elevator shaft one above the other. The two cars are coupled to a common counterweight via a carrying rope.
The use of several elevator cars in one elevator shaft is also described in U.S. Pat. No. 5,699,879. In this case it is suggested that a separate counterweight be associated with each car, wherein the counterweights are positioned one above the other.
In order to avoid the cars being limited in their movability, when several cars are arranged one above the other in one elevator shaft, due to the fact that all the floors can no longer be serviced by all the cars, the use of additional passing or storage areas, which are arranged at the upper and at the lower end of the elevator shaft, is suggested in U.S. Pat. No. 5,419,414. Passing areas of this type do, however, entail quite considerable construction costs.
It is suggested in the Japanese publication JP-A-4-341 479 that passing areas for the elevator cars be arranged in a central area of the elevator shaft. In this respect, two cars are provided in one elevator shaft and are coupled to one another like a pendulum in such a manner that upward travel of the one car requires downward travel of the other car. If one of the cars stops, this automatically leads to the other car also stopping. The transport capacity of such elevator systems is, therefore, limited.
It is the object of the present invention to develop an elevator system of the generic type further in such a manner that it can be produced inexpensively and has an improved transport capacity.